RestTemplate: how to get generic List response [duplicate]

问题

This question already has answers here:

Using Spring RestTemplate in generic method with generic parameter (8 answers)

Closed 12 months ago.

We are using restemplate in a commons package for our application. So we need to use generic types.

I read many solutions about that, but none seems to not work for us, and we constantly get (on the client side):

java.util.LinkedHashMap cannot be cast to nc.gouv.dsf.ranch.model.Pays

Here is the code (sum up):

public List<T> findAll(C criteria) {
[...]
                ResponseEntity<List<T>> response = 
                    restTemplateFactory.getRestTemplate().exchange(
                            url, 
                            HttpMethod.GET, 
                    new HttpEntity<>(createHttpHeaders(srvId)),
                    new ParameterizedTypeReference<List<T>>() {}
                            );          

            return response.getBody();
}

I though ParameterizedTypeReference what the solution to this kind of problems but its doesn't work.

PS: we are using springboot 1.3.1.RELEASE

回答1:

It seems the request is returning a Map and we are trying to cast it into list, hence the exception. Can you try the following:

ResponseEntity<Map<String, Object>> response = 
            restTemplateFactory.getRestTemplate().exchange(
                    url, 
                    HttpMethod.GET, 
            new HttpEntity<>(createHttpHeaders(srvId)),
            new ParameterizedTypeReference<Map<String, Object>>() {}
                    );

来源：https://stackoverflow.com/questions/35834296/resttemplate-how-to-get-generic-list-response